INDEX 



21 



References are to pages 



Soils Continued 



bacteria, beneficent and 



harmful . . . 314-318,345 

 earthworms, fertilizers of 



317-319, 345, 401-402 

 mulching .... 328-329,345 



subsoil 307-310 



surface soil 308 



varieties of 307-310, 319-321, 345 



ventilation of 313 



water vs. . 311-312,319,321-326 



Solar day 33 



Solar family, earth's ; see Solar 



systems 

 Solar systems : 



sun's 5, 10-18 



stars ? 6 



Solids 42,58 



see also Matter 

 Solstices (summer and winter) 30 



Solutions 139-142 



in water 142 



saturated 141 



with salt 142 



Solvents (alcohol, gasoline, tur- 

 pentine, water) 140 



Sound 416-418,423 



wave-motion 417 



medium of hearing . . . 417 



transmission of .... 418 



ear, organ of .... 418 



Specific density of water . . 150 



Specific gravity 47 



Specific heat 84 



Spectroscope 358, 364 



Spectrum 357-358, 364 



Spinal cord . . . .... 407 



Spine (vertebral column) . . 406 



Spits 161-162,549 



Gibraltar 161-162 



harbors of 549 



Spores (of molds and mush- 

 rooms) 399 



Springs (cold and hot) ... 196 



Spring tide 165 



Sprout (of plants) 394 



Stamens (of flowers) .... 387 



Standard time .... 34-50, 40 



daylight saving .... 37, 40 



Standard time Continued 



International Date Line . 35, 40 

 time meridians of .... 35 

 variations from exact time . 34 



Starch (a carbohydrate) 382, 426- 



429 



Stars 3-10,18-19,347 



constellations of . . . . 9-10, 19 

 distances from earth and sun 



6-8, 18 

 Arcturus, light from . . 7 



light of 4-9, 347 



Milky Way 5 



North Star 9 



positions of 5, 8, 9 



sizes of 6 



suns, as 6, 18 



solar systems 6 



Steel and iron (as magnet- 

 making minerals) .... 476 



Stems (of plants) 373-379, 421-422 



buds of 378 



functions of 375 



propagation on 377 



structure of 373-377 



types of 375,422 



varieties of 375 



Steppes (of Russia) .... 285 



Stigma (of flowers) .... 387 



Stock-yard by-products (as 

 fertilizers) 316 



Stomach 420 



gastric juice 420 



see also Digestion 



Stomata (of plant-leaves) . . 386 



Storms 125,221-231 



adiabatic cooling and heat- 

 ing, a cause of .... 125 



anti-cyclonic 224 



cyclonic .... 221,226-231 

 see also Winds 



Streams ; see Rivers 



Submarines 150-151 



Submergence . . . 150-151,303 

 a factor in surface-changes . 303 



in water 150-151 



of submarines .... 150-151 



Subsoil 309 



Substances ; see Matter 



